Blender Git Loki

Sculpt: Use more saturated colors in the cursor

The previous cursor colors were chosen to match the toolbar icon color,
but the contrast on top of the default matcaps was not enough. This
commit uses more saturated colors, which are more visible on top of the
default matcaps.

Reviewed By: jbakker, billreynish

Differential Revision: https://developer.blender.org/D6194